A biopsy is the main test used to diagnose mesothelioma. It involves removing a sample of tissue, which is examined under a microscope by a specialist doctor called a pathologist. The pathologist looks for cell changes to work out if the tumour is mesothelioma and, if so, the type of mesothelioma cells present.
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The main types of mesothelioma cells
Mesothelioma is usually classified according to how the cells look under a microscope (although in about 27% of cases, the classification is unknown). There are three main types of mesothelioma cells:
Epithelioid – cells look similar to normal mesothelial cells. This is the most common type, making up about 70% of cases.
Sarcomatoid – cells have changed and look like cells from fibrous tissue. This type makes up about 10–15% of cases.
Mixed or biphasic – has epithelioid and sarcomatoid cells. This type makes up about 10–15% of all cases.
Ways to take a biopsy for mesothelioma
A biopsy can be taken in different ways. The choice of biopsy will depend on your general health and fitness, and how suitable the tumour is for sampling using one of the methods described below.
Keyhole surgery (VATS or laparoscopy) is the most common biopsy technique as both tissue samples and fluid can be removed for testing. However, obtaining a sample can be challenging, so a respiratory physician or gastroenterologist, radiologist, surgeon and pathologist may all be involved.
Video-assisted thoracoscopic surgery (VATS)
This is used to obtain a tissue sample from the lining of the lungs (pleura).
How it’s done – You will be given a general anaesthetic, then a thin tube with a light and camera will be inserted through a few small cuts in your chest. Tissue samples can be taken through the tube and sent to a laboratory for testing.
If fluid has built up around the lungs and is causing breathlessness, it can be drained during the VATS and you may have a pleurodesis to prevent the fluid building up again. After the VATS you’ll need painkillers.
CT-guided core biopsy
A CT-guided core biopsy may be used instead of VATS or laparoscopy when there is a large mass but no fluid.
How it’s done – You will have a local anaesthetic to numb the area, and a hollow needle will be inserted through the skin to remove a thin core of tissue from the lining of the lungs. A CT scan will be used to guide the needle into position. During a CT-guided core biopsy, you will need to lie still on a table for about 30 minutes. Afterwards you will stay in the radiology suite for a couple of hours so you can be watched for possible complications (such as bleeding or a collapsed lung).
Draining fluidWhen you first have symptoms of mesothelioma, you are likely to have a build-up of fluid in the space around your lungs. Fluid around the lungs (pleural effusion) can make it hard to breathe. Before suggesting further tests or treatment, your doctor may drain the built up fluid to ease symptoms. When fluid is drained from the pleura, it is called a pleural tap, pleurocentesis or thoracentesis. Draining the fluid may be done at the same time as VATS or laparoscopy. |
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A/Prof Brian McCaughan, Cardiothoracic Surgeon, Chris O’Brien Lifehouse, NSW; Theodora Ahilas, Principal Lawyer, Maurice Blackburn Lawyers, NSW; Prof David Ball, Director, Lung Service, Peter MacCallum Cancer Centre, VIC; Shirley Bare, Consumer; Cassandra Dickens, Clinical Nurse Consultant, Cancer Care Coordinator – Thoracic Malignancies, Sunshine Coast University Hospital, QLD; Penny Jacomos, Social Worker, Asbestos Diseases Society of South Australia, SA; A/Prof Thomas John, Medical Oncologist, Senior Clinical Research Fellow, Austin Health, and Olivia Newton-John Cancer Research Institute, VIC; Victoria Keena, Executive Officer, Asbestos Diseases Research Institute, NSW; Penny Lefeuvre, Consumer; Jocelyn McLean, Mesothelioma Support Coordinator, Asbestos Diseases Research Institute, NSW; Prof David Morris, Peritonectomy Surgeon, St George Hospital and University of New South Wales, NSW; Caitriona Nienaber, 13 11 20 Consultant, Cancer Council Western Australia; Prof Anna Nowak, Medical Oncologist, Sir Charles Gairdner Hospital, and Professor of Medicine, School of Medicine and Pharmacology, The University of Western Australia, WA; Prof Jennifer Philip, Palliative Care Specialist, St Vincent’s Hospital, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, VIC; Nicole Taylor, Acting Lung Cancer and Mesothelioma Cancer Specialist Nurse, The Canberra Hospital, ACT. We also thank the health professionals, consumers and editorial teams who have worked on previous editions of this title. Previous editions of this title and related resources were funded in part by the Heads of Asbestos Coordination Authorities and a donation from Lyall Watts.
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